Reference Values for PCT in Lower Respiratory Tract Infections (LRTI) Patients

Procalcitonin (PCT) Reference ranges/ Interpretation of results

The absolute level of PCT concentrations increase with increasing severity of disease. However, as an expression of individually different immune responses and different clinical situations, the same focus of infection may be associated with varying individual elevations in PCT concentrations.

The optimal cut-off values ranges of PCT are variable and dependent on:
  • The clinical setting (eg, emergency room, ICU, post-operative or trauma patients)
  • The site and extent of the infection (eg, RTI, meningitis, abdominal infection)
  • Co-morbidities (eg, immunosuppression)
  • The clinical implications drawn (eg diagnosis, prognosis, antibiotic stewardship)

Therefore, clinicians should use the PCT results in conjunction with other laboratory findings and clinical signs of the patient and interpret the concrete values in the context with the clinical situation of the patient. The reference ranges below are therefore given for orientational purpose only.

differential diagnosis of lrti

CAVE: For use of PCT for differential diagnosis of lower respiratory tract infections (LRTI) only sensitive PCT assays can be used which can precisely detect PCT concentrations of 0.1 ng/ml.

Sensitive B·R·A·H·M·S PCT assays available:

SIRS, Sepsis, Severe Sepsis, and Septic Shock are categorized according to the criteria of the consensus conference of the American College of Chest Physicians/Society of Critical Care Medicine. See PCT & Sepsis Reference Values

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